Space Beacons are being destroyed and plundered for the argonite used in their construction. A V-ship from Earth investigates and having narrowly missed the gang of space pirates starts putting teams onto the remaining space beacons in the area. The Tardis arrives on beacon Alpha 4 but so do the pirates who kill the team left there and break the space station up with the Tardis crew trapped in a different section to their ship.

The Space Pirates: Not to be confused with the CBeebies show of the same name or the Doctor Who serial the Pirate Planet. In fact listening to it the thing that came to mind was "Star Trek" with the concept of a patrolling space fleet. However it's virtually impossible for Star Trek to have had an influence on this Doctor Who story as it hadn't yet been shown in the UK. That would soon change so it's not inconceivable that the Doctor Who team may have had a sneak peak at the BBC's new American import.

The noise the pirates use to detonate the explosives sounds very familiar, I'm pretty certain it's the Yeti spheres' beeping communication noise.

It's a quick return to scripting duties for Robert Holmes here, fresh from his debut show the Krotons. While this serial was in production Terrance Dicks was busy sorting out The Seeds of Death and writing The War Games with Malcolm Hulke so Derrick Sherwin is one last time credited as Script Editor. However he's by this point effectively producing the show due Peter Bryant's ill health. This is the last story for which Bryant will be credited as Producer.